Dmitri Monakhov wrote: Could it be that in the first case you will have merges, thus creating fewer/larger I/O requests? Running iostat -x during the two runs, and watching the output is a good first place to start. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html